1. Field of the Invention
This application relates to security devices and methods of manufacture thereof. In particular, this application relates to security seals for shipping containers that incorporate a bolt.
2. Description of the Related Art
Security seals are used widely in the shipping industry to provide a tamper-resistant closures for many different types of shipping containers and shipping receptacles. In one common example, one or more security seals are placed on the exterior of a shipping container (e.g., a container that is placed on a cargo ship for international shipping) after the contents of the container are verified.
There are many reasons for which a shipper might want (or be required) to seal a container after the contents of the container are placed therein. For example, for international shipping, customs requires that the freight container be sealed. In addition, in domestic shipping situations, there is often a need to seal a freight container for purposes of preventing tampering with the contents of the freight container.
Regardless of the reasons for which a security seal is employed, the security seal is expected to perform its intended function—namely to discourage opening of the container and to indicate if the container has been opened during transit for any reason. If the seal is broken, the recipient of the container will be able to quickly and easily determine that the container has been opened so that the recipient may reject the shipment, take appropriate corrective action, etc.
Of the many types of container seals that are known, one variety is referred to as a “bolt seal” because the security seal incorporates a bolt into its construction. Reference will now be made to FIGS. 20-23, which assist in providing an overview of the related art.
It is noted that the following discussion is intended to provide an overview of the related art to facilitate an understanding of various aspects of the invention described herein. Before delving into the discussion of the related art, a brief overview of some of the specific deficiencies in the art is provided.
Bolt seals in the art typically are made from metal. As such, the seals do not include any indicia of color that may be used by a shipper to identify characteristics either of the shipping container or the contents of that container. For example, a shipper may wish to utilize seals with indicia of color to identify containers that are designated for international destinations. In another example, with respect to the contents of the container, the shipper may wish to employ different colored seals to indicate if the contents are fragile or perishable.
There are no standards in the shipping industry with respect to the use of color for particular shipments or containers. Accordingly, shippers may establish their own color schemes for the seals that they employ. In this regard, the colors that shippers select are individual (or specific) for that shipper.
As may be immediately apparent, when metal bolt seals are used to seal a container, without further modification, the seal has no color other than the color of the metal from which the seal is constructed. As would be appreciated by those skilled in the art, shippers typically do not apply color to the seals that they purchase because the application of color (e.g., by painting the seal) requires labor, which takes time and, therefore, adds cost.
Accordingly, in response to an increased interest from shippers, a need has arisen for bolt seals that incorporate color as an identifying feature. One difficulty with the manufacture of seals incorporating color lies in the fact that bolt seals traditionally are made from metal. Once a manufacturer chooses to supply bolt seals with indicia of color, the cost of the bolt seals increases for several reasons. Accordingly, at least from the standpoint of the manufacturer, a need has now arisen for bolt seals that incorporate indicia of color but that are not prohibitively expensive to manufacture.
Before explaining in greater detail some reasons why, at least with respect to the prior art, manufacturing and supplying bolt seals with indicia of color is more expensive, a general overview of related bolt seals is provided below.
FIG. 20 illustrates features of a bolt seal that is described in U.S. Pat. No. 4,802,699.
The bolt seal 10 includes a bolt 12 and a nut 14. The bolt 12 includes a head 16 connected to an elongated shaft 18. The elongated shaft 18 includes a tapered end 20, a plurality of parallel rings 22 and a plurality of grooves or notches 24. The nut 14 includes an end cap 26 and an interior security member 28, both of which cooperate with a first C-shaped ring 30 and a second C-shaped ring 32.
When the security seal 10 is installed on a freight container, the shaft 18 of the bolt 12 is inserted typically through structural members on the doors of shipping container. The nut 14 is then slid onto the shaft 18 until the nut 14 engages the parallel rings 22 on the shaft 18. The first and second rings 30, 32 are smaller in diameter than the shaft 18. Accordingly, when the C-shaped rings 30, 32 are introduced to the tapered end 20 of the shaft 18, the C-shaped rings 30, 32 expand to slide easily along the shaft 18. Once the C-shaped rings 30, 32 reach one of the grooves 24, however, the C-shaped rings 30, 32 return to their unexpanded shapes and, thereby, prevent the nut 14 from sliding in the opposite direction. A plurality of grooves 24 are provided to accommodate various sizes of shipping containers, as would be appreciated by those skilled in the art.
FIG. 21 illustrates a variation on the security seal 10 shown in FIG. 20. In this example, the security seal 34 also includes a bolt 36 and a nut 38. The bolt 36 includes a head 38 and a shaft 40. The end 42 of the shaft 40 opposite the head 38 has a tapered surface 42. A groove 44 is disposed in the shaft 40 near the tapered end 42 of the shaft 40. The nut 46 in this example has a cylindrical body with a closed end 48, defining a central bore 50. The central bore 50 defines a contoured bottom end 52. The central bore 50 defines a groove 54 in which a C-shaped ring 56 is disposed.
When the tapered end 42 of the bolt 36 is inserted into the central bore 50, the C-shaped ring 56 is captured by the grooves 44, 54 so that the nut 46 cannot be removed easily from the bolt 36. As also indicated, the nut 46 has a cylindrical outer surface 58 and a flat surface 60 on its bottom end.
In both of these prior art examples, the bolts 12, 46 and the nuts 14, 46 are made from metal and do not include color identifiers.
In response to shipper interest in bolt seals that are provided with indicia of color, manufacturers have employed approaches like the one illustrated in FIGS. 22-23. The bolt seal is illustrated in FIGS. 22-23 may be found in U.S. Pat. No. Des. 514,425.
The bolt seal 68 includes a bolt 70, the cylindrical shaft of which is visible. A first end cap 72 is disposed over the nut (not shown) that engages one end of the bolt 70. The nut has the same construction as the nut 46 illustrated in FIG. 21. The first end cap 72 presents a broad surface 76 into which label information may be inscribed. The second end cap 74 is molded around the head of the bolt and presents a second surface 78 into which label information may be inscribed.
In the example illustrated in FIGS. 22 and 23, the first end cap 72 and the second end cap 74 are injection molded over the head of the bolt and over the body of the nut. While injection molding is entirely adequate for providing indicia of color, injection molding increases the cost of the bolt seal 68, which is disadvantageous in the marketplace.
In addition, because the first and second end caps 72, 74 are injection molded around the bolt 70, the end caps 72, 74 are permanently attached to the bolt and the nut. Accordingly, for the manufacturer that needs to have a variety of colors on hand for immediate shipment to a shipper, there is an increased cost associated with warehousing the myriad of colors in which the bolt seals 68 are manufactured.
In view of the foregoing, there are a number of issues raised by the prior art for which a solution is sought.